1. Field of the Invention
The present invention relates to a socket for an electrical part adapted to carry out an inspection or test of an electrical part such as semiconductor device (called as “IC package” hereinlater).
2. Related Art of the Invention
In a recent art of this field, it has been required for an IC package to be operated at an improved high speed, which involves difficulty of exactly measuring the electrical performance of the electrical part by using a conventionally existing socket therefore.
Under such circumstances, there is proposed a socket capable of responding to high frequency as disclosed, for example, in Japanese Patent Laid-open Publication No. JP H9-161870-A, which is shown in FIG. 8.
With reference to FIG. 8, there is such disclosure as “elastomer connector 1 exists between an IC package 2 and a printed circuit board 3 for inspection, a solder ball 5 of the IC package 2 and a terminal 6 of the printed circuit board 3 are electrically connected to each other through a fine metal wire 4 provided for the elastomer connector 1”.
However, with such socket as mentioned above, in the repeated use, solder component of the solder ball 5 of the IC package 2 adheres to the fine metal wire 4 of the elastomer connector 1, and hence, electrical performance is degraded and deteriorated, resulting in shortage of usable life time, and in a case when it is desired to re-use such degraded socket, it is necessary to entirely exchange the expensive elastomer connector with new one, being disadvantageous.
Furthermore, there is also provided a socket responding to high frequency use utilizing a probe-pin. In such socket, however, in order to ensure a suitable contacting pressure, it is required to flexibly combine a plurality of metal members or parts or to incorporate a spring or like, which will lead to a complicated or large structure of the entire socket. Moreover, in order to make short the dimensions of such socket, there exists critical limit or like, thus being difficult to suitably apply to the high frequency use.